It is not uncommon to find folks promoting breastfeeding as a way to boost their children’s immune systems as an alternative rather than an adjunct to vaccination. On the West Coast, this philosophy is hindering the regions efforts in achieving high enough vaccine coverage to prevent disease as noted in the Herald this week.
When it comes to prevention of infectious diseases breastfeeding is certainly not a universal elixir.
It is well accepted that infants receive specific immunity in the form of antibodies from their mother through the placenta before birth and in breast milk if they are being breast fed against a range of infections. These antibodies are temporary and wane within weeks to months. Whether a baby receives any antibodies against a particular disease and whether these antibodies are actually protective are dependent on a range of variables. Here are two examples which are of particular concern to communities who do not vaccinate. The two most infectious diseases known to man.
Pertussis (whooping cough)
Unless a mother has been recently infected with pertussis or very recently vaccinated she will not pass antibody on to her infant either transplacentally or in breast milk. This is simply because she will have no circulating antibody herself to pass on. The only way to protect baby is to vaccinate baby. Interesting study some years ago in region in Italy where pertussis was endemic in the absence of the use of vaccine. While breastfeeding appeared protective against acute lower respiratory infection, breast-fed infants had the same risk for hospitalisation with pertussis-like illness as bottle fed babies. Breastfeeding does not protect against pertussis. NZ currently has a pertussis epidemic. Pertussis can be lethal in young infants.
While infants may receive protective levels of antibody against measles from their mother, this rapidly wanes leaving them vulnerable. There is little or no measles antibody passed through breast milk. A study in Belgium found even when mothers had experienced clinical measles disease the antibodies passed to their babies only endured for a median of up to 3.78 months. Breastfeeding did not impact on the decay time of antibody. There is certainly some evidence that breastfeeding can reduce the severity of measles infection. A large British study investigated if breastfeeding modified clinical measles and also the effect of immunisation. Breastfeeding was associated with a modest reduction in measles diagnosis but in contrast measles vaccination was highly associated with a low risk for measles. In other words, breastfeeding helps a bit but vaccination is very effective.
Best of all – breastfeeding improves the immune response to some vaccines!